!set lang_exists=yes

Works in virtual classes are organized in worksheets.

Each virtual class can have up to 64 worksheets, and each worksheet can
contain up to 64 work items. A work item can be any Wims module: exercise,
tool, or other.

Each worksheet has a status. The status of a newly created worksheet is
under preparation, which allows work items be added and modified.
This is the only status under which the worksheet can be deleted. A
worksheet under preparation is only visible by the supervisor.

When the supervisor activates a worksheet under preparation, the sheet
becomes active. It can no longer be modified or deleted, and
participants will be able to work on it.

Each worksheet has an expiration date. Passing this date, it becomes
expired, in which case participants will continue to see it and be
able to work on it, but no score will be registered.

And an expired sheet can become hidden, in which case participants
no longer see it (but it is always visible to the supervisor).

The supervisor can manually switch a worksheet between active,
expire and hidden (in any direction).

